Module vulkano::buffer [] [src]

Location in memory that contains data.

A Vulkan buffer is very similar to a buffer that you would use in programming languages in general, in the sense that it is a location in memory that contains data. The difference between a Vulkan buffer and a regular buffer is that the content of a Vulkan buffer is accessible from the GPU.

High-level wrappers

The low level implementation of a buffer is UnsafeBuffer. However, the vulkano library provides high-level wrappers around that type that are specialized depending on the way you are going to use it:

  • CpuAccessibleBuffer designates a buffer located in RAM and whose content can be directly written by your application.
  • DeviceLocalBuffer designates a buffer located in video memory and whose content can't be written by your application. Accessing this buffer from the GPU is usually faster than the CpuAccessibleBuffer.
  • ImmutableBuffer designates a buffer in video memory and whose content can only be written once. Compared to DeviceLocalBuffer, this buffer requires less processing on the CPU because we don't need to keep track of the reads and writes.

If you have data that is modified at every single frame, you are encouraged to use a CpuAccessibleBuffer. If you have data that is very rarely modified, you are encouraged to use an ImmutableBuffer or a DeviceLocalBuffer instead.

If you just want to get started, you can use the CpuAccessibleBuffer everywhere, as it is the most flexible type of buffer.

Buffers usage

When you create a buffer object, you have to specify its usage. In other words, you have to specify the way it is going to be used. Trying to use a buffer in a way that wasn't specified when you created it will result in an error.

You can use buffers for the following purposes:

  • Can contain arbitrary data that can be transferred from/to other buffers and images.
  • Can be read and modified from a shader.
  • Can be used as a source of vertices and indices.
  • Can be used as a source of list of models for draw indirect commands.

Accessing a buffer from a shader can be done in the following ways:

  • As a uniform buffer. Uniform buffers are read-only.
  • As a storage buffer. Storage buffers can be read and written.
  • As a uniform texel buffer. Contrary to a uniform buffer, the data is interpreted by the GPU and can be for example normalized.
  • As a storage texel buffer. Additionnally, some data formats can be modified with atomic operations.

Using uniform/storage texel buffers requires creating a buffer view. See the view module for how to create a buffer view.

Reexports

pub use self::cpu_access::CpuAccessibleBuffer;
pub use self::cpu_pool::CpuBufferPool;
pub use self::device_local::DeviceLocalBuffer;
pub use self::immutable::ImmutableBuffer;
pub use self::sys::BufferCreationError;
pub use self::view::BufferView;
pub use self::view::BufferViewRef;

Modules

cpu_access

Buffer whose content is accessible to the CPU.

cpu_pool
device_local

Buffer whose content is read-written by the GPU only.

immutable

Buffer that is written once then read for as long as it is alive.

sys

Low level implementation of buffers.

view

View of a buffer, in order to use it as a uniform texel buffer or storage texel buffer.

Structs

BufferInner

Inner information about a buffer.

BufferSlice

A subpart of a buffer.

BufferUsage

Describes how a buffer is going to be used. This is not an optimization.

Traits

BufferAccess

Trait for objects that represent a way for the GPU to have access to a buffer or a slice of a buffer.

TypedBufferAccess

Extension trait for BufferAccess. Indicates the type of the content of the buffer.